Method and system for ensuring continuous data flow between re-transmitters within a chaincast communication system

ABSTRACT

A method and system for performing chaincast communication to multiple communication systems (e.g., computer systems) within a system of coupled electronic devices (e.g., the Internet). The present invention provides a system wherein a broadcast source communicates primary broadcast information (e.g., encoded audio radio content, encoded audio/video television content, etc.) to a first group of electronic devices. The first group of electronic devices can be instructed by a chaincast manager to then communicate (e.g., forward or retransmit) the broadcast information to other electronic devices which devices can also be instructed to communicate to more devices, etc., thereby reducing the bandwidth requirements of the communication channel between the broadcast source and the first group of electronic devices. The chaincast manager, coupled to the Internet, is used to track and manage which devices are forwarding broadcast information to which other devices. The chaincast manager is also used to monitor the packet rates between the electronic devices. In response to the packet rates falling below a pre-determined threshold value, the transmission re-routes communications to provide better communication load sharing across the system. The chaincast communication system may also include a number of secondary broadcast servers for broadcasting secondary information content (e.g., advertisement, emergency information, community information, etc.) to be rendered independently of the primary broadcast information content.

RELATED US APPLICATION

The instant application is a continuation-in-part of co-pending U.S.patent application Ser. No. 09/253,117, filed on Feb. 19, 1999, andentitled “Chaincast Method and System for Broadcasting Information toMultiple Systems within the Internet,” by Jozsef Kiraly, and assigned tothe assignee of the present invention, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the field of digital informationcommunication. More specifically, the present invention relates to thefield of computer implemented digital broadcast communication ofinformation over the Internet.

2. Related Art

The Internet is a large network made up of a number of smaller networks.It is made up of more than 100,000 interconnected networks in over 100countries, comprised of commercial, academic and government networks. Ithas become commercialized into a worldwide information highway and database, containing information on virtually every subject known tohumankind.

The proper and efficient use of the great amount of informationavailable on various Internet sites has the potential of providingInternet users with a variety of information desired for businesses andindividuals. In particular, those users interested in certain segmentsof the information available on the Internet or those users interestedin certain specific Internet sites could benefit tremendously fromhaving their specific information of interest available to them in anautomated and interesting manner. Moreover, such users would benefitgreatly from being constantly and automatically updated on newinformation as the new information becomes available on their sites ofinterest.

Due to the prevalence and popularity of the World Wide Web (also calledthe “Web”) servers around the world, a great number of Internet usersare particularly interested in receiving updated information of interestto them from various World Wide Web servers on the Internet. By way ofbackground, the World Wide Web is an Internet facility that linksdocuments locally and remotely. The Web document is called a Web page,and links in the page let users jump from page to page (hypertext)whether the pages are stored on the same server or on servers around theworld. The pages are accessed and read via a Web browser such asNetscape Navigator or Microsoft Internet Explorer.

The Web has become the center of Internet activity because, among otherreasons, Web pages, containing both text, graphics and multi-mediacontent are easily accessible via a Web browser. The Web contains thelargest collection of online information in the world, and the amount ofinformation is increasing. Current schemes for accessing a Web documentrequire typing in the URL (Uniform Resource Locator) address of the homepage in the Web browser. From there, the user starts “surfing” throughthe Internet via hypertext links to other documents that can be storedon the same server or on a server anywhere in the world.

The shear size of the information available on the Internet and the Webhas made it a necessity for individuals and businesses to efficientlyand constantly sift through the available information in order to findand organize the information that is of interest. More importantly, itis crucial for content providers to efficiently and effectively transmittheir information to those desiring to receive the information. Stateddifferently, individuals and businesses realize that the availability ofinformation itself does not result in a competitive edge unless theinformation can be efficiently sent from the content provider to thereceiver and further unless the information is of interest and of valueto the business or the individual.

FIG. 1 illustrates a system 70 regarding one use of the Internet. Insystem 70, the Internet 40 is used to provide a communication channelbetween a broadcast source 60 (e.g., a Web server) and a number ofreceiving devices (e.g., Web browsers) or “users” 10, 12, 14. A digitalbroadcast signal, e.g., representing some audio/video/multi-mediacontent or program such as a radio program or television program, can bebroadcast in encoded digital packets from the source server 60 to thereceivers 10, 12, 14. Although the digital broadcast content is the samefor each receiver, a separate communication stream, comprising separatedigital data packets, is required for each receiver that is coupled tothe Internet. Therefore, three separate communication streams 20, 21 and22 are shown as being broadcast directly from server 60 onto theInternet 40. Stream 20 is identified and communicated for receiver 10,stream 21 is identified and communicated for receiver 12 and stream 22is identified and communicated for receiver 14. Further, the users 10,12, 14 have to visit the Web site providing the audio/video/multi-mediacontent in order to establish the communication streams 20, 21, 22.

As a result of the above, it is clear that the number of users(receivers) that can receive broadcast information on the Internetsimultaneously from one server 60 is limited mainly by the connectionspeed of the connection between the server 60 and the Internet 40because each stream 20, 21, 22 consumes available bandwidth. Forexample, assuming it is desired to broadcast a radio program over theInternet to users, e.g., that visit the web site of the server 60 (FIG.1). Depending on the compression algorithm used, and on the number ofusers that want to listen to the program simultaneously, the server 60needs to be connected to the Internet 40 with a speed of at least N×Kbytes/s, where K is the bandwidth requirement for one user and N is thenumber of users able to listen to the program simultaneously. Assumingthe server connection to the Internet 40 allows up to 1.5 Mbit/sbandwidth, the number of listeners will be limited to roughly 300 perserver, assuming roughly 5 Kbits/s bandwidth requirement per user.

Although this figure appears large, in reality the bandwidth of theconnection hardware between the server 60 and the Internet 40 actuallyimparts a substantial limitation to the number of receivers that cansimultaneously receive content from the server. While more sophisticatedconnections with higher bandwidths can be used, this substantiallyincreases the costs associated with providing the content from theserver 60 to the receivers 10, 12 and 14.

Accordingly, what is needed is a cost effective method of providingcontent to many users pseudo-simultaneously over the Internet. What isfurther needed is a method and system that is able to provide broadcastcommunication content to many users, pseudo simultaneously, withoutbeing limited to the bandwidth constraints of the server to Internetconnection. The present invention provides such a solution.

SUMMARY OF THE DISCLOSURE

A method and system are described herein as an embodiment of the presentinvention for implementing an Internet radio device for receiving and/ortransmitting audio information over the Internet. The Internet radiodevice can be implemented as a stand alone electronic radio device whichis coupled to the Internet or the Internet radio device can beimplemented as a software package operable on a host computer systemwhich is coupled to the Internet. In either case, the Internet radiodevice does not require a browser for interfacing with other Internettransmitters (“Internet radio station transmitters”). The Internet radioincludes a graphical user interface (GUI) with which a user caninterface in order to receive audio radio programming from an Internetradio station transmitter. The radio device receives a list of Internetradio station transmitters that are registered with a chaincast manager(CCM), also coupled to the Internet. The GUI renders this list to theuser. The user can sort or select from this list based on desiredlanguage, country, or station names. To hear a radio program, a user canselect a station from this list. Data received by a radio device can beretransmitted in chaincast mode from the radio device to other radiodevices that want to listen to the same radio program.

Using the chaincast broadcasting architecture, described below, aprimary information transmitter (PIT) within the CMM manages the flow ofdigitally encoded audio information from the Internet radio stationtransmitters to and among the coupled Internet radio devices.Specifically, the CMM manages the communication links between theInternet radio station transmitters (e.g., primary broadcast servers)and the radio devices and manages the communication links betweenInternet radio stations performing chaincasting.

In Ham radio mode, one radio device can select another radio device tobe the “radio station,” in which case a communication channel is openedbetween the radio devices so that voice and/or other digitally encodedinformation (e.g., video, HTML documents, Web pages, multi-media, etc.)can be exchanged between the radio devices. In this mode, the GUIcontains a “transmit” button or key. Using the chaincast broadcastingarchitecture, described below, each radio device acts as a primarybroadcast server to communicate information to an associated radiodevice. In Ham radio mode, a listing of radio devices can be shown inthe radio GUI, in an analogous fashion as radio station listings aredisplayed. A user can then select a listed radio device with which tocommunicate.

A method and system is also described herein for a chaincastbroadcasting architecture which performs chaincast communication tomultiple communication systems within a system of coupled electronicdevices. In one implementation the electronic devices can be computersystems and the system of coupled electronic devices includes theInternet. The present invention provides a system wherein a broadcastsource communicates primary digital broadcast information (e.g., encodedaudio radio content, encoded audio/video television content, etc.) to afirst group of electronic devices. The first group of electronic devicescan be instructed by a chaincast manager to then communicate (e.g.,forward or re-transmit) the broadcast information to other electronicdevices which devices can also be instructed to communicate to moredevices, etc., thereby reducing the bandwidth requirements of thecommunication channel between the broadcast source and the first groupof electronic devices. The communication is “chaincast” because theforwarding from one device to another, to another, etc., creates alogical communication “chain” originating from the broadcast server andtraversing to and through the receiving devices. The resultingcommunication is pseudo-simultaneous with respect to the receivingdevices due to the slight delay introduced in buffering andretransmitting the broadcast content from device to device, etc.

A computer implemented chaincast manager, coupled to the Internet, isused to track and manage which devices are forwarding broadcastinformation to which other devices. In order to ensure continuous dataflow along the communication “chains,” the chaincast manager is alsoused to monitor the packet rates between the electronic devices. Inresponse to the packet rates falling below a pre-determined thresholdvalue, the chaincast manager re-routes communications between thedevices to provide better communication load sharing across the systemand to provide more efficient content communication between the devices.

According to one embodiment of the present invention, the chaincastcommunication system may include a number of primary broadcast serversfor broadcasting primary information content (e.g., radio programs, TVprograms, multi-media content, etc.). The chaincast communication systemmay also include a number of secondary broadcast servers forbroadcasting secondary information content (e.g., advertisement,emergency information, community information, etc.) to be renderedindependently of the primary broadcast information content. Users of theelectronic devices of the present chaincast communication system canselect from one of these primary broadcast servers from which theydesire to receive primary broadcast information. In one embodiment, thecontent of the secondary broadcast information the users receive isdetermined by the chaincast manager. In another embodiment, users of thepresent chaincast communication system can select a general subjectmatter that they desire to receive as the secondary broadcastinformation.

According to the present invention, an electronic device forretransmitting or forwarding broadcast information may be a computersystem configured for receiving and re-transmitting broadcastinformation to other electronic devices. The electronic device mayinclude a re-transmission buffer for temporarily holding data packetsreceived from an upstream device before rendering and for temporarilyholding data packets after rendering for subsequent retransmission toanother electronic device. The electronic device also monitors a numberof unrendered data packets stored therein. When the number of unrendereddata packets falls below a threshold level, the electronic devicesignals the near empty condition to the chaincast manager such that adifferent upstream re-transmitter can be assigned to supply informationto the electronic device.

Embodiments of the present invention include the above and furtherinclude a communication system comprising: a plurality of informationreceiver and retransmitter devices (IRRTs) coupled to the Internetwherein each IRRT is for receiving and rendering broadcast informationand for selectively retransmitting the broadcast information to anotherIRRT; a plurality of primary broadcast servers coupled to the Internet,each for originating respective primary broadcast information that ischaincast among a group of IRRTs of said plurality of IRRTs; a pluralityof secondary broadcast servers coupled to the Internet and each fororiginating respective secondary broadcast information that is chaincastamong a group of IRRTs of the plurality of IRRTs; and a chaincastmanager coupled to the Internet and for registering the plurality ofprimary and secondary broadcast servers and for scheduling informationtransfers of the respective primary broadcast information to IRRTs basedon broadcast requests generated by the IRRTs to the chaincast manager.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a prior art information broadcast system using theInternet.

FIG. 2 illustrates a general purpose computer system which can be usedas an electronic device, a user, or a server in accordance with thepresent invention.

FIG. 3A is an exemplary communication diagram of the chaincastcommunication method of the present invention.

FIG. 3B is another exemplary communication diagram of the chaincastcommunication method of the present invention.

FIG. 3C is another exemplary communication diagram of the chaincastcommunication method of the present invention.

FIG. 4 is an Internet connection diagram of the devices of FIG. 3A.

FIG. 5A illustrates a name table managed by the transmission schedulerfor the user devices of the present invention.

FIG. 5B illustrates a name table managed by the transmission schedulerfor information transmitters of the present invention.

FIG. 6 is a flow chart diagram illustrating steps of the chaincastcommunication method of the present invention.

FIG. 7 is a flow chart diagram illustrating steps of the chaincastcommunication method of the present invention.

FIG. 8A is an exemplary communication diagram of the chaincastcommunication method according to one embodiment of the presentinvention.

FIG. 8B is another exemplary communication diagram of the chaincastcommunication method according to one embodiment of the presentinvention.

FIG. 9 is an exemplary user interface of a software-implemented Internetradio software with chaincasting capability according to the presentinvention.

FIG. 10 is a logical block diagram illustrating a transmission bufferaccording to one embodiment of the present invention.

FIG. 11 is a graphical user interface of a radio device in accordancewith one embodiment of the present invention for Ham radio mode.

FIG. 12A is a logical block diagram of the chaincasting communicationarchitecture for Ham radio mode communications between radio devices ofone embodiment of the present invention.

FIG. 12B illustrates a chaincast communication configuration for thesecondary broadcast servers which can operate in parallel with thetransmissions of the primary broadcast servers of FIG. 12A.

FIG. 13 is an exemplary configuration a chaincast communication systemaccording to yet another embodiment of the present invention.

FIG. 14 is a flow chart diagram illustration operations of the chaincastcommunication system illustrated in FIG. 13 in furtherance of oneembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of the present invention, achaincast system and method, including an Internet radio device, forcommunicating digital broadcast content to multiple users, pseudosimultaneously, without being constrained to the bandwidth of theserver-to-Internet connection, numerous specific details are set forthin order to provide a thorough understanding of the present invention.However, it will be recognized by one skilled in the art that thepresent invention may be practiced without these specific details orwith equivalents thereof. In other instances, well known methods,procedures, components, and circuits have not been described in detailas not to unnecessarily obscure aspects of the present invention.

Notation and Nomenclature

Some portions of the detailed descriptions which follow are presented interms of procedures, steps, logic blocks, processing, and other symbolicrepresentations of operations on data bits within a computer memory.These descriptions and representations are the means used by thoseskilled in the data processing arts to most effectively convey thesubstance of their work to others skilled in the art. A procedure,computer executed step, logic block, process, etc., is here, andgenerally, conceived to be a self-consistent sequence of steps orinstructions leading to a desired result. The steps are those requiringphysical manipulations of physical quantities. Usually, though notnecessarily, these quantities take the form of electrical or magneticsignals capable of being stored, transferred, combined, compared, andotherwise manipulated in a computer system. It has proven convenient attimes, principally for reasons of common usage, to refer to thesesignals as bits, values, elements, symbols, characters, terms, numbers,or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout the present invention,discussions utilizing terms such as “processing” or “computing” or“translating” or “calculating” or “determining” or “displaying” or“recognizing” or the like, refer to the action and processes of acomputer system, or similar electronic computing device, thatmanipulates and transforms data represented as physical (electronic)quantities within the computer system's registers and memories intoother data similarly represented as physical quantities within thecomputer system memories or registers or other such information storage,transmission or display devices.

Computer System 112

Aspects of the present invention, described below, are discussed interms of steps executed on a computer system. Aspects of the presentinvention are also discussed with respect to an Internet systemincluding electronic devices and servers coupled together within theInternet platform. A “server” and an “electronic device” or “user” canbe implemented as a general purpose computer system. Although a varietyof different computer systems can be used with the present invention, anexemplary computer system 112 is shown in FIG. 2.

In general, computer systems 112 that can be used by the presentinvention comprise an address/data bus 100 for communicatinginformation, a central processor 101 coupled with the bus for processinginformation and instructions, a volatile memory 102 (e.g., random accessmemory) coupled with the bus 100 for storing information andinstructions for the central processor 101 and a non-volatile memory 103(e.g., read only memory) coupled with the bus 100 for storing staticinformation and instructions for the processor 101. Computer system 112also includes a data storage device 104 (“disk subsystem”) such as amagnetic or optical disk and disk drive coupled with the bus 100 forstoring information and instructions and a display device 105 coupled tothe bus 100 for displaying information to the computer user.

Also included in computer system 112 is an alphanumeric input device 106including alphanumeric and function keys coupled to the bus 100 forcommunicating information and command selections to the centralprocessor 101. Generally, alphanumeric input device 106 is called akeyboard or keypad. System 112 also includes a cursor control ordirecting device 107 coupled to the bus for communicating user inputinformation and command selections to the central processor 101. Thecursor directing device 107 is typically displaced through user movementwhich causes a cursor image displayed on screen 105 to move accordingly.Within the context of the present invention, the cursor directing device107 can include a number of implementations including a mouse device,for example, a trackball device, a joystick, a finger pad (track pad),an electronic stylus, an optical beam directing device with opticalreceiver pad, an optical tracking device able to track the movement of auser's finger, etc., or any other device having a primary purpose ofmoving a displayed cursor across a display screen based on userdisplacements. Computer system 112 also includes a microphone 109 forreceiving voice inputs.

Computer system 112 of FIG. 2 can also include an optional signalgenerating device 108 coupled to the bus 100 for interfacing with othernetworked computer systems, e.g., over the Internet. The display device105 of FIG. 2 utilized with the computer system 112 of the presentinvention may be a liquid crystal device, other flat panel display,cathode ray tube, or other display device suitable for creating graphicimages and alphanumeric characters recognizable to the user. In oneembodiment of the present invention, computer system 112 could be aWindows Operating System based computer system having an x86architecture processor 101, or an Apple Operating System based Macintoshcomputer, for example.

Chaincast Communication of the Present Invention

FIG. 3A illustrates an exemplary configuration in accordance with thepresent invention for performing “chaincast” communication within theInternet system. Within FIG. 3A, a broadcast server 260 supplies abroadcast content that a number of electronic devices a1-aj, b1-bk, c1and c2 (coupled to the Internet) desire to receive “pseudo”simultaneously. This broadcast content can be of any nature or characterthat would be desired to be received by a number of userssimultaneously, e.g., an encoded audio program (e.g., a radio program),an encoded audio/visual program (e.g., a television program), aninstructional seminar, a software program, an HTML document, multimediacontent, etc. The broadcast content is typically encoded into individualdata packets and broadcast digitally. The digital broadcast content isreceived pseudo-simultaneously because of the small latencies involvedin buffering and retransmitting the broadcast content between variouselectronic devices of FIG. 3A.

The chaincasting method of the present invention does not require a highspeed connection between the broadcast server 260 and the Internet 300(FIG. 4) and still allows practically an unlimited number of users toreceive and render the same digitally broadcasted program. Thechaincasting method can be applied to any kind of informationbroadcasting, including radio and television (TV), Web-content and otherinformation. For simplicity, a radio program is described herein as anexample of broadcast content. However, it should be appreciated thataudio/visual and/or other multimedia content could also be used as thedigital broadcast.

The present invention, instead of transmitting the information to manyusers directly from a server, causes the server to transmit theinformation directly only to a few users (e.g., a1-aj of FIG. 3A) andthen instructs these few users to forward (or “retransmit” or “relay”)the information to the other users (e.g., b1-bk, c1 and c2) as needed.This is chaincasting. The present invention changes the paradigm ofinformation providers and information consumers because all users canrelay information to others thereby reducing the communication burden onthe server-to-Internet connection. Instead of the old paradigm, thepresent invention creates an information sharing community (FIG. 3A)that utilizes the Internet resources optimally. Chaincasting causes alogical chain of the same broadcast signal from the broadcast server 260to other electronic devices and then to other electronic devices, etc.

In the example of FIG. 3A, users a1-aj receive the broadcast contentdirectly from the broadcast server 260 via separate information streams310-313, which are supported on the bandwidth resources of theconnection hardware situated between the Internet 300 (FIG. 4) andserver 260. These streams each contain digital encoded packets that makeup the digital broadcast content. In one example, the broadcast contentrepresents a radio program and is therefore digital encoded audioinformation. The number of users, j, is set based on the bandwidthsupported by the connection hardware located between the Internet 300(FIG. 4) and server 260. Users a1-aj are instructed, by thecomputer-implemented transmission scheduler 200, to respectively forwardthe broadcast content to users b1-bk in the fashion shown in FIG. 3A.For instance, a separate stream 320 is used between users a1 and b1; aseparate stream 324 is used between users a2 and b2; a separate stream326 is used between users a3 and b3; and a separate stream 330 is usedbetween users aj and bk. Users b1 and b3 are instructed, by thetransmission scheduler 200, to forward again the broadcast content tousers c1 and c2 in the fashion shown in FIG. 3A. A separate stream 322is used between users b1 and c1 and a separate stream 328 is usedbetween users b3 and c2.

Logical communication “chains” are formed in this communicationarchitecture, e.g., chain 1 is a1-b1-c1; chain 2 is a2-b2; chain 3 isa3-b3-c2 and chain 4 is aj-bk. Software loaded within each user can beused to provide the forwarding functionality which is controlled by thetransmission scheduler 200.

Each user of FIG. 3A, registers with the transmission scheduler 200which maintains and tracks the communication links established betweenthe users. The transmission scheduler 200 load balances between theusers so that the communication load is balanced to reduce transmissionlatencies. Load balancing can be performed to maintain uniform chainsizes. For example, if one user is supplying retransmissions to arelatively larger number of other users (e.g., a chain size of four),then some of the receiver users can be moved from this chain such thatthey receive the information from other established chains. It ispossible for one user to receive broadcast information from more thanone other user; the duplicate data can be ignored.

In the chaincast communication architecture, all users send statusupdate messages to the transmission scheduler 200. Transmissionscheduler 200 can use these status update messages to re-routecommunication links when the transmission activity of one user becomestoo slow, or shuts down. For instance, assume user b3 of FIG. 3A shutsdown. The result is shown in FIG. 3B where the transmission scheduler200 created a new link 340 to directly connect user a3 to user c2. Thetransmission scheduler 200 creates and maintains the new link 340 (aswell as all other links). Assuming rendering pipelines are large enoughwithin each user, the transfer or reassignment between communicationsources from FIG. 3A to FIG. 3B (with respect to user c2) can beperformed transparently to user c2.

As another example, assume user b3 of FIG. 3A decides to download alarge software program from the Internet, consuming a substantialportion of his bandwidth. In this case, user c2 begins to receivebroadcast data at a rate that is too slow based on a predeterminedthreshold. User c2 reports this in a periodic message to thetransmission scheduler 200. The transmission scheduler 200 thenreassigns the source for user c2. The resulting re-transmission pathwaysare illustrated in FIG. 3C when the transmission scheduler 200 created anew link 340 to directly connect user a3 to user c2 while maintainingthe link 326 between user a3 and user b3. The detailed mechanisms fordetecting a slow or dead link between users in accordance with oneembodiment of the present invention are described herein to follow.

FIG. 4 is a high level diagram of the Internet connection system of thedevices of FIG. 3A. The users, a1-aj, b1-bk, c1 and c2 are coupled tothe Internet 300. The broadcast server 260 and the transmissionscheduler 200 are coupled to the Internet. Server 260 and scheduler 200can reside in separate computer systems or can reside within the samecomputer system. Internet connection 202 is located between thebroadcast server 200 and the Internet 300 and has a finite communicationbandwidth that dictates the number of users a1-aj that can directlyreceive broadcast information packets from the server 260.

FIG. 5A illustrates that the transmission scheduler 200 can be coupledwith a name server 400 that contains a listing of IP addresses 412 foreach user and each user has an associated unique name (column 410). Thisname server 400 can be used to establish communication links (e.g., tosupport Internet telephony) between users. If a first user wants to talkto a second user, the first user informs transmission scheduler 200 ofthe communication link between itself and name of the second user. Thetransmission scheduler 200 then opens a direct link between the firstand second users, over the Internet 300. For example, links 320, 322,324, 326, 328, 330 shown in FIG. 3A can be opened using the name serverin this fashion, but the establishment of these links and thedesignation of users are controlled by the transmission scheduler 200.

Name server 400 also contains user information (e.g., name, address,phone number, etc.) of each user (column 414). In addition, name server400 includes a listing of the status information (column 416) of theuser devices associated with each of the users, a listing of the sources(column 420) from which the user devices receive broadcast content, anda listing of the targets (column 422) to which the user devices relaybroadcast content. The status information (column 416) is used by thetransmission scheduler 200 to determine the availability of a particularuser device for relaying broadcast content. Name server 400 furtherincludes geographical location information (column 418).

FIG. 5B illustrates that transmission scheduler 200 can be coupled witha name server 430 that contains a listing of IP addresses 434 for eachinformation transmitter (e.g., broadcast server 260) and eachinformation transmitter has an associated unique station name (column436). The station name may be the name of the radio station or TVstation that the information transmitter carries. This name server 430is used to establish communication links (e.g., to support Internettelephony) between information transmitters and the users. If a userwants to receive broadcast information from an information transmitter,the user informs transmission scheduler 200 of the name of theinformation transmitter or a station name. The transmission scheduler200 then opens a direct link between the information transmitter and theuser over the Internet 300. For example, links 310, 311, 312, 313 shownin FIG. 3A, FIG. 3B and FIG. 3C can be opened using the name server inthis fashion, but the establishment of these links and the designationof users are controlled by the transmission scheduler 200.

Name server 430 also contains registration information (e.g., maximumnumber of user devices permitted, etc.) of each information transmitter(column 438). In addition, name server 430 includes a listing of thetargets (column 446) to which the information transmitters transmitbroadcast content. A listing of the geographical location of theinformation transmitters (column 440), a listing of the language inwhich the broadcast is made (column 442) and a listing of the status ofthe information receivers (column 444) are also included in name server430. It should be appreciated that the transmission scheduler 432 andthe name server 430 of the present embodiment may be implemented withina primary broadcast server for chaincasting primary content and within asecondary broadcast server for chaincasting second content. Primary andsecondary broadcast servers will be discussed in greater details furtherbelow.

Scheduling Operations and Method for Maintaining Continuous Data FlowWithin a Chaincast Communication System

An example is given to illustrate the scheduling operations and themethod for maintaining continuous data flow within a chaincastcommunication system of the present invention. In the following example,the chaincast communication system of the present invention includes oneor more broadcast servers, a chaincast server and a number ofinformation receivers and re-transmitters (IRRTs). On a broadcast server(e.g., broadcast server 260) is placed software that is operating as amulti-channel information transmitter. Individual broadcast servers maybe operated by content providers (e.g., radio stations, televisionstations, or other multi-media content providers) for providinginformation on the Internet. On the chaincast server (or anotherbroadcast server) is placed software that is operating as: 1) achaincast manager (CCM); 2) a name server; and 3) transmission scheduler(e.g., transmission scheduler 200). The CCM functions to coordinate andsupervise the operations of the name server and the transmissionscheduler. In the present embodiment, each IRRT includes a computersystem (analogous to computer system 112) and has an informationrendering process, e.g., a radio software program (“Internet radio”),operating that allows broadcast digital packets to be decoded to therebyrender a perceptible image and/or an audible sound, e.g., a radioprogram, originated by the multi-channel information transmitter.

FIG. 6 is a flow chart diagram illustrating the scheduling operations ofthe chaincast communication system according to an embodiment of thepresent invention. As illustrated, at step 605, when an informationtransmitter is activated, it will register itself with the chaincastmanager (CCM), and will inform the CCM the identity of the broadcastinformation source (e.g., a radio station). According to one embodimentof the present invention, an information transmitter is responsible forchaincasting information from only one broadcast information source.However, in the present embodiment, a broadcast server may includemultiple information transmitters. Therefore, a broadcast server may beused to chaincast information originated from multiple informationsources.

At step 607, the information transmitter digitizes broadcast informationfrom the information source into data packets and adds an identifier toeach of the data packets. The identifier, according to the presentembodiment, is a time stamp indicating the time a data packet iscreated. The broadcast information, however, is not immediatelyforwarded or re-transmitted to an IRRT. Rather, the broadcastinformation is temporarily stored within a transmission buffer of thebroadcast server. In the present embodiment, broadcast information iscontinuously received by the information transmitter. Thus, old datapackets stored within the transmission buffer are continuously discardedto make room for new data packets. Further, the transmission bufferincludes a buffer forward (TBF) portion for storing data packets thatare not yet transmitted, and a buffer past (TBP) portion for storingdata packets that have already been transmitted.

Referring again to FIG. 6, at step 610, when a user (e.g., user A) wantsto receive chaincast information, he/she will turn on or activate aninformation receiver and re-transmitter (e.g., IRRT-x) which willconnect to the CCM and will inform the CCM about its IP address. IRRT-xwill then receive from the CCM a list of available informationtransmitters that are registered with the CCM. Within the presentembodiment, IRRT-x presents the list to user A such that user A canselect the broadcast information that he/she wants to receive. The listmay include alphanumeric representations of names of the radio stations,TV stations, etc., carried by the information transmitters that areavailable to the user. The list may also include alphanumericrepresentations of languages of the radio stations that are available.

At step 615 of FIG. 6, user A then selects an information transmitterand IRRT-x will send this information to the CCM. The IRRT-x is now“tuned” to the selected information transmitter.

At step 620, after the CCM receives the information regarding theselected information transmitter from IRRT-x, the CCM then decideswhether IRRT-x will receive time-stamped data packets directly from theselected information transmitter, or whether IRRT-x will receivetime-stamped data packets from another IRRT which is already tuned tothe selected information transmitter.

At step 622, if it is determined that no other IRRTs are suitable forrelaying the time-stamped data packets, CCM will instruct the selectedinformation transmitter to begin transmitting time-stamped data packetsto this IP address (the IP address of IRRT-x).

At step 623, if an IRRT (IRRT-y) that is already tuned to the sameinformation transmitter is available and has sufficieint bandwidth, theCCM will instruct IRRT-y to relay the time-stamped data packets toIRRT-x according to the chaincast approach as discussed above (FIG. 3A,FIG. 3B and FIG. 3C).

At step 625, IRRT-x receives time-stamped data packets from theinformation transmitter and begins to render the time-stamped datapackets. At the same time, IRRT-x will store data packets to be renderedin its transmission buffer. According to one embodiment, data packetsthat have been rendered will not be immediately discarded. Rather,rendered packets will be temporarily stored in the transmission bufferfor subsequent re-transmission to another IRRT.

At step 655, as the information stored in the transmission buffer ofIRRT-x is rendered and as the transmission buffer is draining, IRRT-xgenerates requests to its chaincast source (e.g., the informationtransmitter or another IRRT) to download more data. Particularly, in thepresent embodiment, IRRT-x is configured to generate a request as thetransmission buffer is draining past a “Buffer Low” level. The requestsgenerated by IRRT-x may also include a time stamp of the last datapacket received by IRRT-x such that its source may begin transmissionwith the next data packet.

In this manner, a user of the chaincast communication system of thepresent invention will receive the data either directly from the server,over the Internet, or from another user that is already receiving theinformation (in the chaincast mode). The new user can then later beasked to provide, e.g., forward broadcast information to another user.

According to one embodiment of the present invention, the transmissionbuffer of IRRT-x includes a forward buffer (TBF) for storing datapackets to be rendered and a past buffer (TBP) for storing data packetsthat have already been rendered. Further, TBF and TBP are both capableof storing data packets for at least 60 seconds of broadcastinformation.the packet transmission speed is higher than the renderingspeed. Therefore, if the connection remains stable, the TBF buffer willbe close to full all the time. Thus, in the event that the connectionbetween the information transmitter and IRRT-x becomes unstable, theusers will not experience “gaps” in the broadcast information. Problemsassociated with fluctuations in packet rate are also avoided. The TBP,on the other hand, stores data packets that have already been renderedbut may be required for subsequent transmission to a downstream IRRT.

An exemplary transmission buffer 1000 of an IRRT 1001 is illustrated inFIG. 10. As illustrated, transmission buffer 1000 is partitioned by arendering pointer 1030 into two portions: a buffer forward (TBF) 1010for storing the information to be rendered and buffer past (TBP) 1020for storing the information that has already been rendered. Renderingpointer 1030 is pointing to the specific data packet(s) that iscurrently rendered. The transmission buffer 1000 is configured forreceiving and storing time-stamped data packets from a chaincast source(e.g., information transmitter or an upstream IRRT). It is important tonote that the time stamps are also received from the chaincast source.Also illustrated in FIG. 10 is a “near empty” pointer 1040 and a “bufferlow” pointer 1050. According to the present invention, if the number ofdata packets falls below the “buffer low” pointer 1050, IRRT 1001 willsignal its chaincast source to send more data packets. If the number ofdata packets falls below the “near empty” pointer 1040, IRRT 1001 willsignal the CCM to assign another chaincast source for the IRRT 1001. Inthis way, the transmission buffer 1000 will be maintained at full levelsuch that problems with fluctuations in data packet rate are minimized.As data packets are rendered, they are pushed into the TBP 1020 forsubsequent re-transmission to another IRRT, while data packets pushedout from the bottom of TBP 1020 are either discarded or moved to astorage device.

In order to maintain continuous data flow along the communication“chains,” it is important to monitor the packet rates between the IRRTs.In response to the buffer content level falling below a pre-determinedthreshold value, the present invention re-routes communications betweenthe user devices to provide better communication load sharing across thesystem. According to the present invention, the transmission buffers ofthe IRRTs are used to monitor the packet rates. Particularly, each IRRTmonitors a number of unrendered data packets stored within its owntransmission buffers. When the number of unrendered data packets fallsbelow a threshold level, the IRRT signals its near-empty condition tothe CCM such that a different upstream IRRT can be assigned to it.

FIG. 7 is a flow chart diagram illustrating steps of re-routingcommunications within the chaincast communication system of the presentinvention. In the present example, for the purpose of illustration, itis assumed that the connection between an IRRT-b and its upstream IRRT-abecomes very slow. This may be caused by the IRRT-a shutting down orother reasons. Thus, at step 710, the lowered packet rate causes thenumber of unrendered data packets stored within the transmission buffersof the IRRT-b to drop below a predetermined threshold (e.g., “NearlyEmpty” threshold 1040), and triggers it to send a signal indicating thebuffer's near empty condition to the CCM. In addition, at step 710,IRRT-b sends to the CCM the time-stamp of the last data packet that itreceived.

Then, at step 720, the CCM selects another information receiver andretransmitter (IRRT-c) which is tuned to the same informationtransmitter to relay the broadcast information to IRRT-b. If no otherIRRTs are available, then the CCM selects the information transmitter tobroadcast directly to IRRT-b.

At step 730, after IRRT-c (or the information transmitter) is selected,it is instructed by the CCM to forward the data packets to IRRT-bstarting with the packet indicated by the time stamp. Sometimes, IRRT-cmay no longer have the desired data packets. In that case, IRRT-c willbegin transmitting the last data packet contained in its TBP, and somebroadcast information will be lost. However, a small amount data loss isacceptable for broadcast content such as a radio program. In other caseswhere direct transmission is not feasible and where no other IRRTs aretuned to the same information transmitter, the CCM may use an IRRT thatis in a “stand by” mode or that is tuned to a different station to relaythe broadcast information.

Primary and Secondary Information Transmitters

FIG. 8A is another exemplary chaincast communication system 800according to an embodiment of the present invention. Within FIG. 8, aprimary broadcast server 860 a supplies broadcast content to acommunication chain 810 consisting of information receiver andre-transmitters IRRT1-IRRT6. Another primary broadcast server 860 bchaincasts broadcast content to another communication chain 820consisting of information receiver and re-transmitters IRRT7-IRRT11. Yetanother primary broadcast server 860 c chaincasts broadcast content tocommunication chain 830 consisting of information receiver andre-transmitters IRRT12 and IRRT13. Primary broadcast servers 860 a-860 care also called primary information transmitters (PITs). Secondarybroadcast servers 870 a-870 c supply supplemental content to theinformation receiver and re-transmitters IRRT1-IRRT13. In the presentembodiment, information receiver and re-transmitters IRRT1-IRRT13 eachconsists of a computer system running software that is configured forreceiving and retransmitting primary and secondary content to anotheruser device as instructed by a primary information transmissionscheduler (PITS) 855 and a secondary information transmission scheduler(SITS) 857 of chaincast manager (CCM) 850.

Significantly, according to the present invention, the primary broadcastservers 860 a-860 c are configured for chaincasting primary content thatis originated from a radio broadcaster, a TV broadcaster or othermulti-media content provider, and the secondary broadcast servers 870a-870 c are for chaincasting secondary or supplementary content that maynot be originated from radio broadcasters, TV broadcasters ormulti-media content providers. Secondary broadcast servers 870 a-870 care also called secondary information transmitters (SITs). Typically,the primary broadcast servers 860 a-860 c can be operated by theinformation source companies (e.g., radio stations, TV networks) and thesecondary broadcast servers 870 a-870 c (e.g., responsible fortransmitting advertising content) can be operated by Internet serviceproviders or ChainCast, Inc. of California, under the control of thesecondary information transmission scheduler (SITS) 857 of CCM 850. Inthe present embodiment, the SITS coordinates the chaincasting of thesecondary information in a similar manner that the primary broadcastinformation is chaincasted.

As an example, the primary content may be a radio program broadcast byBBC of Great Britain. The secondary content, on the other hand, may beweather information of the location of the user. As another example, thesecondary content may be real-time stock quotes. According to oneembodiment of the present invention, the secondary information may berendered in the background while the primary content (e.g., radioprogram from BBC) is rendered at a louder volume in the foreground. Thesecondary content may also be inserted in between the primary content.The secondary broadcast servers 870 a-870 c may also provide emergencybroadcast information such as earthquake and flood warnings. It shouldbe appreciated that only a few exemplary uses of the secondary broadcastservers 870 a-870 c are described herein and that the secondarybroadcast servers 870 a-870 c may be used to supply all kinds ofinformation to the information receiver and re-transmittersIRRT1-IRRT13. It should be noted that the secondary information may beaudio or visual or any other types of multi-media information.

According to one embodiment of the present invention, the CCM 850 isresponsible for providing a list of secondary content categories to theusers. The users will then be able to select a particular category ofsecondary content that they would like to receive. The secondaryinformation transmitter scheduler (SITS) 857, based on the user-inputs,will then select the appropriate secondary information transmitters(SITs) to provide secondary content pertinent to the selected categoryto the users. As an example, if a user selects a secondary contentcategory for “automobiles,” the SITs will choose an SIT carryingautomobile-related advertisement to chaincast the advertisement to theuser. It should be noted that the secondary content in this case(“automobiles”) can be completely independent of the primary contentthat the user is receiving. In this way, locally relevant informationmay be provided to a user even though the user is tuned to a remoteinformation broadcaster.

It should also be noted that secondary information does not have to betransmitted along the same communication chains defined by the primaryinformation transmitter scheduler. In order words, the SITS does nothave to use the same communication chains defined by the PITS to relaysecondary information. Indeed, the communication topology for thesecondary information can be significantly different from thecommunication topology for the primary information. FIG. 8B illustratesa configuration of the communication chains 880 a-880 d of the chaincastcommunciation system 800 of FIG. 8. As illustrated, secondaryinformation are transmitted along communication chains 880 a-880 d toIRRT1-IRRT13. However, the composition of communication chains 880 a-880d is entirely different form the composition of the communication chains810, 820 and 830 of FIG. 8.

Method and System for Chaincasting Web-Content in Accordance with thePresent Invention

The chaincast paradigm in accordance with the present invention is notonly applicable to radio broadcast and TV broadcast, but is applicableto Web-content, such as HTML-based Web-content, as well. FIG. 13illustrates a chaincast communication system 1300 for performing thechaincast communication method according to an embodiment of the presentinvention. Within FIG. 13, a Web server 1360 supplies Web content to acommunication chains 1310, 1320 and 1330. Communication chain 1310includes Web clients 1370 a-1370 d, communication chain 1320 includesWeb clients 1370 e-1370 h, and communication chain 1330 includes Webclients 1370 i-1370 j. According to the present embodiment each of theWeb clients 1370 a-1370 j is a computer system (e.g., computer system112) operating a Web browser software. Further, in the presentembodiment, the browser software includes a software module (“chaincastplug-in”) 1380.

In the present embodiment, the “chaincast plug-in” module 1380 isconfigured for relaying Web-content from one Web-client to another asinstructed by a chaincast manager (CCM) 850. In the example illustratedin FIG. 13, Web-client 1370 a receives Web-content directly from the Webserver 1360 via information stream 1310. Web client 1370 a includeschaincast plug-in 1380 configured for retransmitting Web-content that itreceived from Web server 1360 to Web-clients 1370 b and 1370 d under theinstructions from CCM 850. Web-clients 1370 b and 1370 d, in turn, relaythe web-content information it received to other Web-clients includingweb-client 1370 c. Web-content is also disseminated in a similar fashionalong communication chains 1320 and 1330.

FIG. 14 is a flow diagram illustrating exemplary operations of thechaincast communication system 1300 in accordance with one embodiment ofthe present invention. As illustrated, at step 1410, when a Web-client(Web-client X) is activated, its chaincast plug-in module 1380 registersthe Web-client with the CCM 850. According to the present invention,step 1410 may include the steps of modifying a name server (e.g., nameserver 400) by adding an IP address and a name ID corresponding to theWeb-client X.

At step 1420, user of the Web-client X attempts to access a Web-pageindicated by an URL. The chaincast plug-in module of Web-client X thenautomatically sends the URL to the CCM 850.

At step 1440, upon receiving the URL, the CCM 850 determines whether theWeb-page indicated by the URL has been recently accessed by or iscurrently being accessed by another Web-client. CCM 850 may alsodetermine the content of the cache memories of the Web-clients whichhave recently accessed the same URL.

At step 1450, if it is determined that another Web-client (Web-client Y)has recently accessed the same URL and possesses all the content of theURL in its cache memory, or if it is determined that Web-client Y iscurrently accessing the same URL, the CCM 850 will direct the Web-clientY to relay the content of the web-page to the Web-client X. In anotherembodiment of the present invention, the source client (Web-client Y)does not have to possess all the content of the URL in its cache memory.In that embodiment, CCM 850 will instruct Web-client Y to selectivelyforward information stored in its cache memory that is related to theURL to Web-client X.

However, at step 1460, if it is determined that no other Web-clients areaccessing the same web-page, the CCM 850 will then communicate the URLthe Web-server corresponding to the URL, and the requested web-page willthen be transmitted directly to Web-client X. In this manner, a Webserver would able to provide “pseudo” simultaneous access to a virtuallyunlimited number of people despite a limited connection bandwidth withthe Internet.

Graphical User Interface of an Internet Radio with ChaincastingCapability According to the Present Invention

According to one embodiment of the present invention, an IRRT can beimplemented as a stand alone electronic radio device which is coupled tothe Internet or the IRRT can be implemented as a software packageoperable on a host computer system which is coupled to the Internet. Ineither case, the Internet radio device does not require a browser forinterfacing with other Internet transmitters (“Internet radio stationtransmitters”). The Internet radio includes a graphical user interface(GUI) with which a user can interface in order to receive audio radioprogramming from an Internet radio station transmitter. The radio devicereceives a list of Internet radio station transmitters that areregistered with a chaincast manager (CCM), also coupled to the Internet.The GUI renders this list to the user. The user can sort or select fromthis list based on desired language, country, or station names. To heara radio program, a user can select a station from this list. Datareceived by a radio device can be retransmitted in chaincast mode fromthe radio device to other radio devices that want to listen to the sameradio program.

FIG. 9 is an exemplary graphical user interface (GUI) 900 of a softwareInternet radio device with chaincasting capability according to thepresent invention. Using the GUI 900, a user can select radio programsthat are chaincasted by primary broadcast server of the presentinvention. As illustrated, GUI 900 includes a window for displaying animage 910 resembling a real radio. Image 910 includes a display region920 for displaying a preprogrammed channel number, the country of originof the selected radio program and the name of the selected radiobroadcaster. In the illustrated embodiment, BBC of Great Britaincorresponding to pre-programmed channel number 5 is displayed in region920.

GUI 900 further includes channel scanning buttons 930 that areresponsive to user inputs. In the one embodiment, when the channelscanning buttons 930 are “clicked” by the user, the IRRT will signal theCCM that a different radio program is selected. The CCM will theninstruct a PIT or another IRRT carrying data packets corresponding tothe newly selected radio program to forward the data packets to theIRRT. GUI 900 further includes a volume control button 940 responsive touser inputs for adjusting the rendering volume. GUI 900 further providesa number of channel programming buttons 950 a-950 f configurable forselecting a pre-programmed radio broadcaster. For example, if a userconfigures the button 950 e to correspond to a particular radio station,the IRRT will send a signal to the CCM indicating the station selected,and the CCM will instruct a PIT or another IRRT carrying that particularstation to forward data packets to the IRRT.

GUI 900 further includes a tool bar 970 through which the user mayaccess a list of available radio stations. In the illustratedembodiment, the radio stations are sorted by country names, languagesand station names such that a user can select a radio station accordingto its country, language, or station name.

Ham Radio Mode Communications Using the Internet Radio Device

FIG. 11 illustrates a graphical user interface (GUI) 1120 used by analternate embodiment of the Internet radio device of the presentinvention. In this embodiment, called Ham radio mode, one Internet radiodevice is allowed to communicate (e.g., transmit information to andreceive information from) with another Internet radio device. The GUI1120 used in this embodiment is similar to the GUI 900 of FIG. 9 exceptas described differently herein.

GUI 1120 contains a display region 1110 in which a listing of registeredradio devices can be displayed according to a selection criterion as setby user-controlled control bar 1150. Within control bar 1150, the usercan select to display all radio devices by their registered country,language or name, etc. After the selection is made, all registered radiodevices (e.g., registered with the CMM 850) fitting that selection aredisplayed in list form in display region 1150. The user can then selectone of those listed radio devices, using up and down scroll keys 940 toscroll through the listing. The radio device running the GUI 1150 canthen communicate with the selected other radio device once a particularradio device from the listing is selected. The information (e.g., audiosignals) transmitted via the Internet from the selected other radiodevice can be received and rendered audible on the radio device runningthe GUI 1150. Also, a transmit key 1105 can be used on the radio devicerunning the GUI 1150 to communicate audio signals to the selected otherradio device via the Internet. When transmitting audio signals, themicrophone 109 (FIG. 2) is used to capture the user's voice and theradio device then digitizes and encodes the audio signals fortransmission over the Internet.

In the exemplary GUI 1150 of FIG. 11, the selected radio device iscalled “USER_NAME” and its country is GBR. Although not shown, itslanguage could be “English.” A radio device can register with more thanone language.

FIG. 12 illustrates a block diagram of the chaincast broadcastarchitecture in one embodiment of the present invention for supportingHam radio broadcasting modes, as described with respect to FIG. 11. Inthis configuration, a first radio device (called “user 1”) is treated asa primary broadcast server 1210 b and communicates with another, secondradio device, 1220 a which acts as an IRRT device to receive signalsbroadcast over the Internet from the first radio device 1210 b. Thefirst radio device 1210 b registers with the PITS 855 of the CMM 850 inthe fashion described above. Also in this configuration, the secondradio device (called “user 2”) is also treated as a primary broadcastserver 1220 b and communicates with the first radio device, 1210 a whichacts as an IRRT device to receive signals broadcast over the Internetfrom the second radio device 1220 b. The second radio device 1220 bregisters with the PITS 855 of the CMM 850 in the fashion describedabove.

It is appreciated that element 1210 a and element 1210 b are the samedevice but element 1210 a represents the first radio device in itscapacity as a primary broadcast server (e.g., to broadcast audiosignals) and element 1210 b represents the first radio device in itscapacity as an IRRT (e.g., to receive audio signals). Moreover, it isappreciated that element 1220 a and element 1220 b are the same devicebut element 1220 a represents the second radio device in its capacity asa primary broadcast server (e.g., to broadcast audio signals) andelement 1220 b represents the second radio device in its capacity as anIRRT (e.g., to receive audio signals). It is appreciated that theinformation exchanged between radio devices in Ham radio mode is notlimited to audio signals and can be audio signals, video signals,multi-media content signals and/or other HTML documents or Web pages.

FIG. 12B illustrates a chaincast communication configuration for thesecondary broadcast servers which can operate in parallel with thetransmissions of the primary broadcast servers l210 b, 1220 b and 860 cof FIG. 12A. In other words, the chaincast groups and the communicationof the secondary information transmitted among these groups can operatein parallel with the chaincast groups of the primary information shownin FIG. 12A. The chaincast groups can be different between those set upfor primary information and those set up for secondary informationbecause the PITS 855 and the SITS 857 are separate. Applying theInternet radio example, as different Internet radios receive their radioprogramming (e.g., the primary information), these devices can alsoreceive secondary information broadcasts (e.g., advertising content inaudio, video or HTML formats). The PITS 855 controls the radiobroadcasting while the SITS 857 controls the advertising transmissions.

As shown in FIG. 12B, the SITS 857 controls the communication ofsecondary information between the secondary broadcast servers 870 a-870c. Server 870 a chaincasts within Internet radio devices 1231, 1233 and1220 a. Server 870 b chaincasts within Internet radio devices 1232 and1230. Server 870 c communicates with Internet radio 1210. Thesechaincast groups can exist in parallel with the chaincast groups shownin FIG. 12A which represent the primary information broadcast (e.g., theradio programming). It is appreciated that the information scheduled bythe SITS 857 is done independently of the Internet radio devices.

The preferred embodiment of the present invention, a chaincast systemand method for communicating digital broadcast content to multipleusers, pseudo simultaneously, without being constrained to the bandwidthof the server-to-Internet connection, is described. While the presentinvention has been described in particular embodiments, it should beappreciated that the present invention should not be construed aslimited by such embodiments, but rather construed according to the belowclaims.

1. A communication system comprising: a plurality of informationreceiver and retransmitter devices (IRRTs) coupled to the Internetwherein each IRRT is for receiving and rendering broadcast informationand for selectively retransmitting broadcast information to anotherIRRT, and wherein each IRRT includes a transmission buffer having abuffer forward portion for storing broadcast information to be renderedand a buffer past portion for storing broadcast information that hasbeen rendered and can be retransmitted to another IRRT, wherein arendering pointer separates said buffer forward and buffer pastportions; a plurality of primary broadcast servers coupled to theInternet, each for originating respective primary broadcast informationthat is chaincast among a group of IRRTs of said plurality of IRRTs; anda chaincast manager coupled to said Internet and for registering saidplurality of primary broadcast servers and for scheduling informationtransfers of said respective primary broadcast information to IRRTsbased on broadcast requests generated by said IRRTs to said chaincastmanager.
 2. A communication system as described in claim 1 furthercomprising a plurality of secondary broadcast servers coupled to theInternet and each for originating respective secondary broadcastinformation that is chaincast among a group of IRRTs of said pluralityof IRRTs.
 3. A communication system as described in claim 2 wherein saidchaincast manager is also for scheduling information transfers of saidsecondary broadcast information to IRRTs.
 4. A communication system asdescribed in claim 3 wherein said chaincast manager is also forsupplying a respective IRRT with a list of all registered primarybroadcast servers in response to a request by said respective IRRT forsaid list.
 5. A communication system as described in claim 3 whereinsaid primary broadcast information is digitally encoded audioinformation representing audio programs and wherein said plurality ofprimary broadcast servers are radio stations.
 6. A communication systemas described in claim 5 wherein each IRRT comprises a computer systemfor rendering a graphical user interface display of a radio device forallowing a user to request one or more of said primary broadcast serversfrom which to receive primary broadcast information.
 7. A communicationsystem as described in claim 3 wherein said primary broadcastinformation is digitally encoded audio/visual information representingaudiovisual programs and wherein said plurality of primary broadcastservers are television stations.
 8. A communication system as describedin claim 3 wherein said primary broadcast information is digitallyencoded audio/visual information representing audiovisual programs andwherein said plurality of primary broadcast servers are multi-mediacontent providers.
 9. A communication system as described in claim 3wherein said secondary broadcast information is digitally encoded audioinformation representing advertising content and wherein said pluralityof secondary broadcast servers are advertisers.
 10. A communicationsystem as described in claim 3 wherein said secondary broadcastinformation is digitally encoded audio/visual information representingadvertising content and wherein said plurality of secondary broadcastservers are advertisers.
 11. A communication system as described inclaim 3 wherein said secondary broadcast information is digitallyencoded information representing news material.
 12. A communicationsystem comprising: a plurality of information receiver and retransmitterdevices (IRRTs) coupled to the Internet wherein each IRRT is forreceiving and rendering broadcast information and for selectivelyretransmitting broadcast information to another IRRT, and wherein eachIRRT includes a transmission buffer having a buffer forward portion forstoring broadcast information to be rendered and a buffer past portionfor storing broadcast information that has been rendered and can beretransmitted to another IRRT, wherein a rendering pointer separatessaid buffer forward and buffer past portions; a plurality of primarybroadcast servers coupled to the Internet and each for originatingrespective radio broadcast information that is chaincast among a groupof IRRTs; a plurality of secondary broadcast servers coupled to theInternet and each for originating respective advertisement broadcastinformation that is chaincast among a group of IRRTs; and a chaincastmanager coupled to said Internet and for registering said plurality ofprimary and secondary broadcast servers and for scheduling informationtransfers of said radio broadcast information to IRRTs based onbroadcast requests generated by said IRRTs to said chaincast manager andwherein said chaincast manager is also for supplying a respective IRRTwith a list of all registered primary broadcast servers in response to arequest by said respective IRRT for said list.
 13. A communicationsystem as described in claim 12 wherein said chaincast manager is alsofor scheduling information transfers of said advertisement broadcastinformation to IRRTs.
 14. A communication system as described in claim13 wherein said radio broadcast information is digitally encoded audioinformation representing radio programs and wherein said plurality ofprimary broadcast servers are radio stations.
 15. A communication systemas described in claim 14 wherein each IRRT comprises a computer systemfor rendering a graphical user interface display of a radio device forallowing a user to request one or more of said primary broadcast serversfrom which to receive radio broadcast information.
 16. A method ofcommunicating broadcast information over the Internet comprising thesteps of: a) causing a primary server to communicate a first stream ofdata packets representing primary broadcast information to a first userdevice and rendering said primary broadcast information thereon, whereinsaid server and said first user device are coupled to the Internet, andwherein said first user device includes a first transmission bufferhaving a buffer forward portion for storing broadcast information to berendered and a buffer past portion for storing broadcast informationthat has been rendered and can be retransmitted to another user device,wherein a first rendering pointer separates said buffer forward andbuffer past portions; b) causing said server to communicate a secondstream of data packets representing said primary broadcast informationto a second user device and rendering said primary broadcast informationthereon, wherein said second user device is coupled to the Internet andconfigured for rendering said primary broadcast information, and whereinsaid second user device includes a second transmission buffer having abuffer forward portion for storing broadcast information to be renderedand a buffer past portion for storing broadcast information that hasbeen rendered and can be retransmitted to another user device, wherein asecond rendering pointer separates said buffer forward and buffer pastportions; c) causing said first user device to communicate a thirdstream of data packets representing said primary broadcast informationto a third user device and rendering said primary broadcast informationthereon, wherein said third user device is coupled to the Internet andconfigured for rendering said primary broadcast information, and whereinsaid third user device includes a third transmission buffer having abuffer forward portion for storing broadcast information to be renderedand a buffer past portion for storing broadcast information that hasbeen rendered and can be retransmitted to another user device, wherein athird rendering pointer separates said buffer forward and buffer pastportions; d) monitoring a packet rate of said third stream; and f) inresponse to said packet rate falling below a pre-determined rate,causing said second user device to communicate a fourth stream of datapackets representing said primary broadcast information to said thirduser device.
 17. A method as recited in claim 16 wherein said step (d)comprises the steps of: monitoring a number of unrendered data packetsstored in a retransmission buffer of said third user device; and inresponse to said number of unrendered data packets dropping below apre-determined level, causing said third user device to signal achaincast manager to select said second user device.
 18. A method asrecited in claim 16 further comprising the steps of: adding a fourthuser device on the Internet; and causing said third user device tocommunicate a fifth stream of data packets representing said primarybroadcast information to said fourth user device, and wherein saidfourth user device includes a fourth transmission buffer having a bufferforward portion for storing broadcast information to be rendered and abuffer past portion for storing broadcast information that has beenrendered and can be retransmitted to another user device, wherein afourth rendering pointer separates said buffer forward and buffer pastportions.
 19. A method as recited in claim 18 wherein said step ofadding comprises the steps of: registering said fourth user device witha chaincast manager, wherein said chaincast manager is coupled to theInternet; and said chaincast manager instructing said third user deviceto communicate said fifth stream of data packets to said fourth userdevice.
 20. A method as recited in claim 19 further comprising the stepsof: adding a secondary server on the Internet; causing said secondaryserver to communicate a fifth stream of data packets representingsecondary broadcast information to said first user device and renderingsaid secondary broadcast information on said first user device; andcausing said first user device to communicate a sixth stream of datapackets representing said secondary broadcast information to said thirduser device and rendering said secondary broadcast information on saidthird user device.
 21. A method as recited in claim 20 wherein said stepof adding comprises the steps of: registering said secondary server witha chaincast manager, wherein said chaincast manager is coupled to theInternet; and said re-transmission instructing said secondary server tocommunicate said fifth stream of data packets to said first user deviceand instructing said first user device to communicate said sixth streamof data packets to said third user device.
 22. A method as recited inclaim 20 further comprises the step of said third user device renderingsaid primary broadcast information simultaneously with said secondarybroadcast information.
 23. A method as recited in claim 16 wherein saidfirst, second and third user devices each comprises a hardware Internetradio device.
 24. A method as recited in claim 23 wherein said primarybroadcast information comprises content broadcast by a radio station.25. A method as recited in claim 16 wherein said first, second and thirduser devices each comprises a computer system configured for renderingsaid primary broadcast information and for re-transmitting said primarybroadcast information to another computer system coupled to theInternet.
 26. A method of communicating Web content over the Internetcomprising the steps of: a) causing a Web server to communicate a firststream of data packets representing content of an URL (UniversalResource Locator) to a first user device and causing said first userdevice to render said content thereon when said URL is accessed by saidfirst user device, and wherein said first user device includes a firsttransmission buffer having a buffer forward portion for storing datapackets to be rendered and a buffer past portion for storing datapackets that have been rendered and can be retransmitted to another userdevice, wherein a first rendering pointer separates said buffer forwardand buffer past portions; and b) causing said first user device tocommunicate a second stream of data packets representing said content ofsaid URL to a second user device and causing said second user device torender said content thereon when said second user device accesses saidURL pseudo-simultaneously with said first user device, and wherein saidsecond user device includes a second transmission buffer having a bufferforward portion for storing data packets to be rendered and a bufferpast portion for storing data packets that have been rendered and can beretransmitted to another user device, wherein a second rendering pointerseparates said buffer forward and buffer past portions.
 27. The methodaccording to claim 26 further comprising the steps of: said second userdevice receiving user inputs indicative of said URL; and causing saidsecond user device to transmit said URL to a chaincast manager, whereinsaid chaincast manager is coupled to the Internet and wherein saidchaincast manager is for scheduling transfers of information among saidWeb server and said first and second user devices.
 28. The methodaccording to claim 26 wherein said first user device and said seconduser device each comprises a computer system.
 29. The method accordingto claim 28 wherein said computer system comprises Web browser softwarehaving a plug-in module with chaincasting capability.
 30. Acommunication system comprising: a plurality of information receiver andretransmitter devices (IRRTs) coupled to the Internet and wherein eachIRRT is operable to receive broadcast information, operable to render aportion of said broadcast information and configured by a chaincastmanager to selectively retransmit a portion of said broadcastinformation to another IRRT, and wherein each IRRT includes atransmission buffer having a buffer forward portion for storingbroadcast information to be rendered and a buffer past portion forstoring broadcast information that has been rendered and can beretransmitted to another IRRT, wherein a rendering pointer separatessaid buffer forward and buffer past portions; a plurality of primarybroadcast servers coupled to the Internet, each operable to originaterespective primary broadcast information that is chaincast among a groupof IRRTs of said plurality of IRRTs; a plurality of secondary broadcastservers coupled to the Internet and each operable to originaterespective secondary broadcast information that is chaincast among agroup of IRRTs of said plurality of IRRTs; and wherein said chaincastmanager is coupled to said Internet and operable to register saidplurality of primary and secondary broadcast servers and operable toschedule information transfers of said respective primary broadcastinformation to IRRTs based on broadcast requests generated by said IRRTsto said chaincast manager.
 31. A communication system as described inclaim 30 wherein said chaincast manager is also operable to scheduleinformation transfers of said secondary broadcast information to IRRTs.32. A communication system as described in claim 31 wherein saidchaincast manager is also for operable to supply a respective IRRT witha list of all registered primary broadcast servers in response to arequest by said respective IRRT for said list.
 33. A communicationsystem as described in claim 31 wherein said primary broadcastinformation is digitally encoded audio information representing audioprograms and wherein said plurality of primary broadcast servers areradio stations.
 34. A communication system as described in claim 33wherein each IRRT comprises a computer system operable to render agraphical user interface display of a radio device operable to allow auser to request one or more of said primary broadcast servers from whichto receive primary broadcast information.
 35. A communication system asdescribed in claim 31 wherein said primary broadcast information isdigitally encoded audiovisual information representing audio/visualprograms and wherein said plurality of primary broadcast servers aretelevision stations.
 36. A communication system as described in claim 31wherein said primary broadcast information is digitally encodedaudio/visual information representing audio/visual programs and whereinsaid plurality of primary broadcast servers are multi-media contentproviders.
 37. A communication system as described in claim 31 whereinsaid secondary broadcast information is digitally encoded audioinformation representing advertising content and wherein said pluralityof secondary broadcast servers are advertisers.
 38. A communicationsystem as described in claim 31 wherein said secondary broadcastinformation is digitally encoded audio/visual information representingadvertising content and wherein said plurality of secondary broadcastservers are advertisers.
 39. A communication system as described inclaim 31 wherein said secondary broadcast information is digitallyencoded information representing news material.